I am someone who doesn't care if someone doesn't buy me a present on my birthday. I don't care if my girlfriend would propose we don't do anything on Valentine's day and maybe go out another time. It doesn't have to be February 14th we celebrate it, or even the month of February, I don't really care. I don't need to have a Christmas tree to celebrate Christmas.

I'm also not very materialistic. I don't want anything for Christmas and I perceive almost everything people buy me as useless.

Just to make things clear, I am not anti-holiday. I am basically the opposite of the girl who cries because her boyfriend gave her just chocolate on Valentine's day but didn't offer her to go out.

Do you attend mass on these religious festivities? IMO if we know the answer to this, then finding that term will be easier
– Mari-Lou ADec 6 '18 at 9:20

1

Non-materialist and non-traditionalist seem to cover some of the aspects of what you're talking about.
– ScottDec 7 '18 at 1:19

@Mari-LouA No, I am atheist. It has nothing to do with beliefs. It is simply that I do not care about these things. It's not that I am forcing myself to be against it
– Cedric MartensDec 10 '18 at 0:56

Wet blanket. This often used more in the sense of active disproval than mere ambivalence. But it works fine when you are expected to make an effort which exceeds your personal enthusiasm. Valentines Day certainly qualifies. Apparently, it comes from throwing a wet blanket on a fire.

noun INFORMAL

a person who spoils other people's fun by failing to join in with or
by disapproving of their activities.